Bond ply materials and circuit assemblies formed therefrom

Abstract

A composition for a bond ply, and a circuit subassembly that comprises such bond ply, are disclosed. The circuit subassembly can have a UL-94 rating of V-0. The composition of the bond ply layer comprises 25 to 45 volume percent of liquid resin; 10 to 40 weight percent of a bromine-containing or phosphorus-containing aromatic compound having a peak melting point of at least about 260° C.; and 5 to 35 volume percent inorganic filler.

What is claimed is: 
     
       1. A bond ply layer, having a thickness of 50 to 400 micrometers formed from a composition comprising:
 25 to 45 volume percent of liquid resin comprising polybutadiene and/or polyisoprene and, in addition, a nitrogen-containing compound having allyl groups, wherein the nitrogen-containing compound is present in an amount of 5 to 15 volume percent, based on total composition and the polybutadiene and/or polyisoprene is present in an amount of 20 to less than 60 volume percent, based on the total resin; 
 10 to 40 weight percent of a bromine-containing or phosphorus-containing aromatic compound having a peak melting point of at least about 260° C.; and 
 5 to 35 volume percent inorganic filler, wherein all percents are calculated based on the bond ply composition absent solvent; 
 wherein the bond ply has a UL-94 rating of at least V-1, a D f  of less than 0.006 at 10 GHz and a D k  of 2 to 10 at 10 GHz. 
 
     
     
       2. The bond ply layer of  claim 1 , further comprising 1 to 25 volume percent of poly(arylene ether). 
     
     
       3. The bond ply layer of  claim 1 , wherein the bromine-containing compound has a wt. % bromine (theoretical) of 50 to 80%, a molecular weight of 500 to 2500, and comprises two to four brominated aromatic rings. 
     
     
       4. The bond ply layer of  claim 1 , wherein the phosphorus-containing aromatic compound is an oxaphosphorinoxide-containing compound represented by the following structure: 
       
         
           
           
               
               
           
         
         wherein each R 1  and R 2  independently represents hydrogen or a C 1 -C 6  hydrocarbyl group, each m can independently represent an integer from 1 to 4, n is on average 2 to 4, and Q is a C 2 -C 24  divalent or trivalent hydrocarbyl group. 
       
     
     
       5. The bond ply layer of  claim 1 , wherein the bromine-containing compound is selected from the group consisting of ethylene bistetrabromophthalide, tetrabromdiphenoxy benzene, decabromodiphenoxy oxide, and ethane-1,2-bis(pentabromo phenyl). 
     
     
       6. The bond ply layer of  claim 4 , wherein the oxaphosphorinoxide-containing aromatic compound is selected from the group consisting of 6H-dibenz[c,e] [1,2] oxaphosphorin, 6,6′-(1,4-ethanediyl)bis-, 6,6′-dioxide; 6H-dibenz[c,e][1,2] oxaphosphorin, 6,6′-(1,4-butanediyl)bis-, 6,6′-dioxide; 6H-dibenz[c,e][1,2] oxaphosphorin, 6,6′-(p-xylenediyl)bis-, 6,6′-dioxide, and combinations thereof. 
     
     
       7. The bond ply layer of  claim 1 , wherein the nitrogen-containing compound contains a triazine ring and allyl groups that are reactive with a resin component of the composition. 
     
     
       8. The bond ply layer of  claim 1 , wherein the composition of the bond ply layer further comprises 5 to 25 weight percent of poly(arylene ether) and 5 to 25 weight percent of an elastomeric polymer, both in solid form. 
     
     
       9. The bond ply layer of  claim 1 , wherein the composition comprises:
 5 to 20 weight percent of poly(arylene ether) and 5 to 20 weight percent of an elastomer, based on the weight of the composition; 
 20 to 30 volume percent of the inorganic filler; and 
 25 volume percent to less than 37 volume percent of the liquid resin, which liquid resin comprises: 
 20 to 40 volume percent polybutadiene or polyisoprene, based on total resin; and 
 5 to 10 volume percent of a nitrogen-containing compound that contains allyl groups. 
 
     
     
       10. The bond ply layer of  claim 1  wherein the liquid resin further comprises 5 to 15 volume percent of a diene reactive monomer. 
     
     
       11. A circuit subassembly, comprising
 at least two circuit laminates, each comprising: 
 a dielectric substrate layer formed from a thermosetting composition; 
 a conductive metal layer bonded to each side of the dielectric substrate layer, wherein at least one of the conductive metal layers of each circuit laminate has been patterned to form a circuit; 
 a bond ply layer disposed between the circuits of on each of the two circuit laminates wherein each of the two sides of the bond ply is in direct contact with a circuit of one of the two circuit laminates, which bond ply layer is the product of a process of lamination in which the bond ply flows and fills areas of the dielectric substrate layer that are not covered by circuit formed by patterned conductive metal layer, wherein the bond ply layer is formed from a composition that, absent solvent, comprises: 
 25 to 45 volume percent of liquid resin comprising polybutadiene and/or polyisoprene and, in addition, a nitrogen-containing compound having allyl groups, wherein the nitrogen-containing compound is present in an amount of 5 to 15 volume percent, based on total composition, and the polybutadiene and/or polyisoprene is present in an amount of 20 to less than 60 volume percent, based on the total resin; 
 10 to 40 weight percent of a bromine-containing or phosphorus-containing aromatic compound having a peak melting point of at least about 260° C.; and 
 5 to 35 volume percent inorganic filler; 
 wherein the circuit subassembly has a UL-94 rating of at least V-0, a D f  of less than 0.006 at 10 GHz and a D k  of less than 2 to 10 at 10 GHz. 
 
     
     
       12. The circuit subassembly of  claim 11 , wherein the composition further comprises
 5 to 20 weight percent of poly(arylene ether) and an elastomer, based on the weight of the thermosetting composition; 
 10 to 40 weight percent, based on the weight of the thermosetting composition, of a bromine-containing or phosphorus-containing aromatic compound having a peak melting point of 260° C. to 500° C.; 
 20 to 30 volume percent of inorganic filler. 
 
     
     
       13. The circuit subassembly of  claim 12 , wherein the liquid resin further comprises a reactive monomer. 
     
     
       14. The circuit subassembly of  claim 11 , wherein the nitrogen-containing compound contains a triazine ring and has allyl groups that are reactive with polybutadiene and/or polyisoprene resin in the bond ply layer. 
     
     
       15. The circuit subassembly of  claim 11 , wherein the inorganic filler is selected from group consisting of silica, titanium dioxide, and combinations thereof. 
     
     
       16. The circuit subassembly of  claim 11 , wherein the bromine-containing aromatic compound has compound has a wt. % bromine, theoretically, of 50 to 80%, a molecular weight of 500 to 2000, and comprises two, three or to four brominated aromatic rings. 
     
     
       17. The circuit subassembly of  claim 11 , wherein the thermosetting resin is selected from the group consisting of 1,2-polybutadiene, polyisoprene, polybutadiene-polyisoprene copolymers, poly(phenylene ether) resins, curable cyclic olefins or their copolymers, and combinations thereof, and wherein the phosphorus-containing aromatic compound is an oxaphosphorinoxide-containing compound represented by the following structure: 
       
         
           
           
               
               
           
         
         wherein each R 1  and R 2  independently represents hydrogen or a C 1 -C 6  hydrocarbyl group, each m can independently represent an integer from 1 to 4, n is on average 2 to 4, and Q is a C 2 -C 24  divalent or trivalent hydrocarbyl group. 
       
     
     
       18. The circuit subassembly of  claim 11 , wherein the dielectric substrate has a thickness of 50 to 1000 micrometers, the bond ply layer has a thickness of 50 to 400 micrometers, and an optional adhesive layer, between the dielectric substrate and each conductive metal layer, has a thickness that is less than 10 percent of the thickness of the dielectric substrate layer. 
     
     
       19. A circuit subassembly, comprising:
 (a) at least two circuit laminates, each comprising: 
 a dielectric substrate layer formed from a thermosetting composition, wherein the thermosetting composition comprises, based on the total weight of the thermosetting composition: 
 10 to 35 wt. % of a polybutadiene and/or polyisoprene resin; 
 30 to 70 weight percent of inorganic filler; and 
 10 to 35 wt. % of a bromine-containing or phosphorus-containing aromatic compound having a peak melting point of at least about 260° C. to about 500° C.; 
 (ii) a conductive metal layer bonded to each side of the dielectric substrate layer, wherein at least one of the conductive metal layers of each circuit laminate has been patterned to form a circuit; and 
 (b) a bond ply layer disposed between the at least two circuit laminates wherein the bond ply is in direct contact with at least one circuit or conductive layer in at least one of at least two circuit laminates, wherein the composition of the bond ply layer is formed from a composition that comprises: 
 polybutadiene and/or polyisoprene in an amount of 20 to less than 60 volume percent, based on the total resin, of which all or part is in the form of liquid resin; 
 25 to 45 volume percent of liquid resin comprising polybutadiene and/or polyisoprene and, in addition, a nitrogen-containing compound having allyl groups, wherein the nitrogen-containing compound is present in an amount of 5 to 15 volume percent, based on total composition; 
 10 to 40 weight percent of a bromine-containing or phosphorus-containing aromatic compound having a peak melting point of at least about 260° C.; and 
 5 to 35 volume percent inorganic filler, wherein all percents are calculated based on the bond ply composition absent solvent; 
 wherein the circuit subassembly has a UL-94 rating of at least V-1, a D f  of less than 0.006 at 10 GHz and a D k  of less than 3.8 at 10 GHz. 
 
     
     
       20. The circuit assembly of  claim 18 , wherein volume percent of filler and the volume percent polybutadiene and/or polyisoprene present in the thermosetting composition of the dielectric substrate layers is at least 5 volume percent greater than in the composition of the bond ply.